When Mack threw down to second baseman Xavier Edwards in the middle of the first inning, the ball hit shortstop Otto Lopez’s warmup toss to first baseman Christopher Morel. Everyone – both on the field and off – stood there in shock.
“I've never done that in my life, and obviously, I just couldn't help but laugh,” Mack said. “It was kind of funny. … If I got a million tries, I might be able to do it [on purpose].”
That unusual throw set the tone for Friday’s series opener, which marked the 10th Major League game for Mack (MLB Pipeline’s No. 44 overall prospect). Miami called him up earlier this month because of his defensive prowess, and the club has given him a chance to showcase it by starting him in nine of 11 games behind the dish since his debut.
Through 78 innings, Mack has no passed balls, one error (throwing variety) and four wild pitches. He entered the night with -1 defensive runs saved.
One number stands out based on his reputation as the 2024 Minor League Gold Glove Award winner at catcher. Despite Mack’s 60-grade arm (20-80 scouting scale), he had thrown out just one of the first 10 basestealers in the Majors. But there’s only so much a backstop can do. So often, success is dependent on times to home from the pitcher or the types of pitches the runner goes on.
Controlling the run game has been an issue for Marlins pitchers since last season, when they allowed 191 steals (most in MLB by 34). Entering the series opener, Miami had permitted an MLB-high 53 stolen bases with a 91.4 percent success rate.
“Obviously, I know my bat can definitely wake up a little bit more,” said Mack, who went hitless in three at-bats to see his OPS drop to .526. “I definitely haven't shown much on that aspect, maybe it's just trying to do too much. But defensively, I feel pretty confident with my ability to receive, block, throw the ball. It's something that they obviously brought me up for, and showing off that, that's a good thing. Obviously the bat, I think, just needs to wake up a little bit, and when that starts to roll, then we just go.”
With Miami already down 7-2 with runners on the corners and two outs in the sixth, Mack threw out speedster Chandler Simpson to end the inning. Here were the Statcast metrics on the play:
- 1.80-second pop time (90th percentile)
- 81.7 mph throw (90th percentile)
- 30.2 ft/sec sprint speed (30 ft/sec is elite)
Simpson entered the opportunity with the fourth-most steals (14) in the Majors, though he has now been caught an MLB-high five times. It helped close the line on right-hander Janson Junk, who surrendered a season-high seven runs on 10 hits in 5 2/3 innings.
“He looks good,” Junk said. “That throw after I came out to get Simpson was amazing and big time, and picked me up in a moment where I was really not in a good head space. I was really pissed off, so just seeing him pick me up like that, and still playing with that fire, is great. And I think overall, just behind the plate, he has good energy, he's encouraging, and I like throwing to him.”
Last weekend, Mack displayed his arm twice.
In Saturday’s game against the Nationals, Mack limited further damage in Washington’s three-run first by recording the first caught stealing of his career. When CJ Abrams attempted to steal second, Mack quickly got rid of the ball with a 1.93-second pop time and 80.2 mph throw. Abrams was initially ruled safe, but a replay review overturned the call.
On Sunday, after Nasim Nuñez nabbed second for his then-MLB-leading 17th steal in the third, he tried advancing to third on a ball that momentarily got away from Mack. He recovered and fired to third, where Javier Sanoja applied the tag.
“His defense has been terrific, and he's really blocked the ball well,” manager Clayton McCullough said. “He's received well. That throw tonight was impressive, the exchange and the accuracy, and what he was able to get on it. Even the other one where [Cedric] Mullins stole, he did all he could, he made a good throw up the line, and [Mullins] just beat it. Joe has played very well behind the plate, and I think that's what we expected coming into this with the ability he has.”